As is disclosed in U.S. Pat. No. 7,454,939, which is incorporated by reference herein, spinal fixation systems may be used in surgery to align, adjust and/or fix portions of the spinal column, i.e., vertebrae, in a desired spatial relationship relative to each other. Many spinal fixation systems employ a spinal fixation rod for supporting the spine and for properly positioning components of the spine for various treatment purposes. The spinal rod, which is generally formed of a metal, such as stainless steel or titanium, may be implanted to correct deformities, prevent movement of vertebral bodies relative to each other or for other purposes. Vertebral anchors, comprising pins, bolts, screws, and hooks, engage the vertebrae and connect the rod to different vertebrae.
Spinal fixation rods are frequently oriented at various angles and positions due to the anatomical structure of the patient, the physiological problem being treated, and the preference of the physician. The size, length and bend of each spinal rod depend on the size, number and position of the vertebrae to be held in a desired spatial relationship relative to each other, which is generally different for each patient. A rod may be bent, as desired, to conform to a desired curvature of the spinal column in one or more of the anatomic planes, in order to fit the rod into the vertebral anchors.
In the current state of the art, bending of spinal rods is typically accomplished using a hand-operated instrument, commonly known as a “French bender.” The French bender is a pliers-like instrument. Because spinal rods are formed of materials that are not easily bendable, such as titanium, a significant amount of force is required to bend the rods. If one hand is used to operate the French bender, then the physician must rotate that hand in an awkward orientation in order to properly view the changing curve of the rod as the handles are squeezed together, and the awkward orientation of the physician's single hand could either prevent the physician from applying the appropriate amount of force required for bending the rod or lead to slippage of the instrument. Accordingly, many physicians use both hands to operate the French bender, which prevents the physician from using a free hand to manipulate the rod in the French bender (or other manual activity).
In view of the foregoing, there exists opportunities for improving upon the structure and operation of a hand-operated instrument for bending a rod, such as a French Bender.